/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.util;

import java.util.Hashtable;
import java.util.Locale;

/**
 * MIME2Java is a convenience class which handles conversions between MIME charset names
 * and Java encoding names.
 * <p>The supported XML encodings are the intersection of XML-supported code sets and those
 * supported in JDK 1.1.
 * <p>MIME charset names are used on <var>xmlEncoding</var> parameters to methods such
 * as <code>TXDocument#setEncoding</code> and <code>DTD#setEncoding</code>.
 * <p>Java encoding names are used on <var>encoding</var> parameters to
 * methods such as <code>TXDocument#printWithFormat</code> and <code>DTD#printExternal</code>.
 * <p>
 * <TABLE BORDER="0" WIDTH="100%">
 * <TR>
 * <TD WIDTH="33%">
 * <P ALIGN="CENTER"><B>Common Name</B>
 * </TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER"><B>Use this name in XML files</B>
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER"><B>Name Type</B>
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER"><B>Xerces converts to this Java Encoder Name</B>
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">8 bit Unicode</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">UTF-8
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">UTF8
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin 1</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-1
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-1
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin 2</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-2
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-2
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin 3</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-3
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-3
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin 4</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-4
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-4
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin Cyrillic</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-5
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-5
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin Arabic</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-6
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-6
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin Greek</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-7
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-7
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin Hebrew</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-8
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-8
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">ISO Latin 5</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ISO-8859-9
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">ISO-8859-9
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: US</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-us
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp037
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Canada</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-ca
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp037
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Netherlands</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-nl
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp037
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Denmark</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-dk
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp277
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Norway</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-no
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp277
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Finland</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-fi
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp278
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Sweden</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-se
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp278
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Italy</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-it
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp280
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Spain, Latin America</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-es
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp284
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Great Britain</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-gb
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp285
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: France</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-fr
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp297
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Arabic</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-ar1
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp420
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Hebrew</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-he
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp424
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Switzerland</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-ch
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp500
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Roece</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-roece
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp870
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Yogoslavia</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-yu
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp870
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Iceland</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-is
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp871
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">EBCDIC: Urdu</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">ebcdic-cp-ar2
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">IANA
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">cp918
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Chinese for PRC, mixed 1/2 byte</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">gb2312
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">GB2312
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Extended Unix Code, packed for Japanese</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">euc-jp
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">eucjis
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Japanese: iso-2022-jp</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">iso-2020-jp
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">JIS
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Japanese: Shift JIS</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">Shift_JIS
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">SJIS
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Chinese: Big5</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">Big5
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">Big5
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Extended Unix Code, packed for Korean</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">euc-kr
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">iso2022kr
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH="33%">Cyrillic</TD>
 * <TD WIDTH="15%">
 * <P ALIGN="CENTER">koi8-r
 * </TD>
 * <TD WIDTH="12%">
 * <P ALIGN="CENTER">MIME
 * </TD>
 * <TD WIDTH="31%">
 * <P ALIGN="CENTER">koi8-r
 * </TD>
 * </TR>
 * </TABLE>
 *
 * @author TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;
 */
public class MIME2Java {

	private static Hashtable<String, String> s_enchash;
	private static Hashtable<String, String> s_revhash;

	static {
		s_enchash = new Hashtable<String, String>();
		//    <preferred MIME name>, <Java encoding name>
		s_enchash.put("UTF-8", "UTF8");
		s_enchash.put("US-ASCII", "8859_1");    // ?
		s_enchash.put("ISO-8859-1", "8859_1");
		s_enchash.put("ISO-8859-2", "8859_2");
		s_enchash.put("ISO-8859-3", "8859_3");
		s_enchash.put("ISO-8859-4", "8859_4");
		s_enchash.put("ISO-8859-5", "8859_5");
		s_enchash.put("ISO-8859-6", "8859_6");
		s_enchash.put("ISO-8859-7", "8859_7");
		s_enchash.put("ISO-8859-8", "8859_8");
		s_enchash.put("ISO-8859-9", "8859_9");
		s_enchash.put("ISO-2022-JP", "JIS");
		s_enchash.put("SHIFT_JIS", "SJIS");
		s_enchash.put("EUC-JP", "EUCJIS");
		s_enchash.put("GB2312", "GB2312");
		s_enchash.put("BIG5", "Big5");
		s_enchash.put("EUC-KR", "KSC5601");
		s_enchash.put("ISO-2022-KR", "ISO2022KR");
		s_enchash.put("KOI8-R", "KOI8_R");

		s_enchash.put("EBCDIC-CP-US", "CP037");
		s_enchash.put("EBCDIC-CP-CA", "CP037");
		s_enchash.put("EBCDIC-CP-NL", "CP037");
		s_enchash.put("EBCDIC-CP-DK", "CP277");
		s_enchash.put("EBCDIC-CP-NO", "CP277");
		s_enchash.put("EBCDIC-CP-FI", "CP278");
		s_enchash.put("EBCDIC-CP-SE", "CP278");
		s_enchash.put("EBCDIC-CP-IT", "CP280");
		s_enchash.put("EBCDIC-CP-ES", "CP284");
		s_enchash.put("EBCDIC-CP-GB", "CP285");
		s_enchash.put("EBCDIC-CP-FR", "CP297");
		s_enchash.put("EBCDIC-CP-AR1", "CP420");
		s_enchash.put("EBCDIC-CP-HE", "CP424");
		s_enchash.put("EBCDIC-CP-CH", "CP500");
		s_enchash.put("EBCDIC-CP-ROECE", "CP870");
		s_enchash.put("EBCDIC-CP-YU", "CP870");
		s_enchash.put("EBCDIC-CP-IS", "CP871");
		s_enchash.put("EBCDIC-CP-AR2", "CP918");

		// j:CNS11643 -> EUC-TW?
		// ISO-2022-CN? ISO-2022-CN-EXT?

		s_revhash = new Hashtable<String, String>();
		//    <Java encoding name>, <preferred MIME name>
		s_revhash.put("UTF8", "UTF-8");
		//s_revhash.put("8859_1", "US-ASCII");    // ?
		s_revhash.put("8859_1", "ISO-8859-1");
		s_revhash.put("8859_2", "ISO-8859-2");
		s_revhash.put("8859_3", "ISO-8859-3");
		s_revhash.put("8859_4", "ISO-8859-4");
		s_revhash.put("8859_5", "ISO-8859-5");
		s_revhash.put("8859_6", "ISO-8859-6");
		s_revhash.put("8859_7", "ISO-8859-7");
		s_revhash.put("8859_8", "ISO-8859-8");
		s_revhash.put("8859_9", "ISO-8859-9");
		s_revhash.put("JIS", "ISO-2022-JP");
		s_revhash.put("SJIS", "Shift_JIS");
		s_revhash.put("EUCJIS", "EUC-JP");
		s_revhash.put("GB2312", "GB2312");
		s_revhash.put("BIG5", "Big5");
		s_revhash.put("KSC5601", "EUC-KR");
		s_revhash.put("ISO2022KR", "ISO-2022-KR");
		s_revhash.put("KOI8_R", "KOI8-R");

		s_revhash.put("CP037", "EBCDIC-CP-US");
		s_revhash.put("CP037", "EBCDIC-CP-CA");
		s_revhash.put("CP037", "EBCDIC-CP-NL");
		s_revhash.put("CP277", "EBCDIC-CP-DK");
		s_revhash.put("CP277", "EBCDIC-CP-NO");
		s_revhash.put("CP278", "EBCDIC-CP-FI");
		s_revhash.put("CP278", "EBCDIC-CP-SE");
		s_revhash.put("CP280", "EBCDIC-CP-IT");
		s_revhash.put("CP284", "EBCDIC-CP-ES");
		s_revhash.put("CP285", "EBCDIC-CP-GB");
		s_revhash.put("CP297", "EBCDIC-CP-FR");
		s_revhash.put("CP420", "EBCDIC-CP-AR1");
		s_revhash.put("CP424", "EBCDIC-CP-HE");
		s_revhash.put("CP500", "EBCDIC-CP-CH");
		s_revhash.put("CP870", "EBCDIC-CP-ROECE");
		s_revhash.put("CP870", "EBCDIC-CP-YU");
		s_revhash.put("CP871", "EBCDIC-CP-IS");
		s_revhash.put("CP918", "EBCDIC-CP-AR2");
	}

	private MIME2Java() {
	}

	/**
	 * Convert a MIME charset name, also known as an XML encoding name, to a Java encoding name.
	 *
	 * @param mimeCharsetName Case insensitive MIME charset name: <code>UTF-8, US-ASCII, ISO-8859-1,
	 *                        ISO-8859-2, ISO-8859-3, ISO-8859-4, ISO-8859-5, ISO-8859-6,
	 *                        ISO-8859-7, ISO-8859-8, ISO-8859-9, ISO-2022-JP, Shift_JIS,
	 *                        EUC-JP, GB2312, Big5, EUC-KR, ISO-2022-KR, KOI8-R,
	 *                        EBCDIC-CP-US, EBCDIC-CP-CA, EBCDIC-CP-NL, EBCDIC-CP-DK,
	 *                        EBCDIC-CP-NO, EBCDIC-CP-FI, EBCDIC-CP-SE, EBCDIC-CP-IT,
	 *                        EBCDIC-CP-ES, EBCDIC-CP-GB, EBCDIC-CP-FR, EBCDIC-CP-AR1,
	 *                        EBCDIC-CP-HE, EBCDIC-CP-CH, EBCDIC-CP-ROECE, EBCDIC-CP-YU,
	 *                        EBCDIC-CP-IS and EBCDIC-CP-AR2</code>.
	 * @return Java encoding name, or <var>null</var> if <var>mimeCharsetName</var>
	 * is unknown.
	 * @see #reverse
	 */
	public static String convert(String mimeCharsetName) {
		return s_enchash.get(mimeCharsetName.toUpperCase(Locale.ENGLISH));
	}

	/**
	 * Convert a Java encoding name to MIME charset name.
	 * Available values of <i>encoding</i> are "UTF8", "8859_1", "8859_2", "8859_3", "8859_4",
	 * "8859_5", "8859_6", "8859_7", "8859_8", "8859_9", "JIS", "SJIS", "EUCJIS",
	 * "GB2312", "BIG5", "KSC5601", "ISO2022KR",  "KOI8_R", "CP037", "CP277", "CP278",
	 * "CP280", "CP284", "CP285", "CP297", "CP420", "CP424", "CP500", "CP870", "CP871" and "CP918".
	 *
	 * @param encoding Case insensitive Java encoding name: <code>UTF8, 8859_1, 8859_2, 8859_3,
	 *                 8859_4, 8859_5, 8859_6, 8859_7, 8859_8, 8859_9, JIS, SJIS, EUCJIS,
	 *                 GB2312, BIG5, KSC5601, ISO2022KR, KOI8_R, CP037, CP277, CP278,
	 *                 CP280, CP284, CP285, CP297, CP420, CP424, CP500, CP870, CP871
	 *                 and CP918</code>.
	 * @return MIME charset name, or <var>null</var> if <var>encoding</var> is unknown.
	 * @see #convert
	 */
	public static String reverse(String encoding) {
		return s_revhash.get(encoding.toUpperCase(Locale.ENGLISH));
	}
}
